This feature issue of JOSA A is based on the 2019 Symposium of the International Colour Vision Society (ICVS) to be held in Riga, Latvia, 5-9 July 2019 (https://www.icvs2019.lu.lv/). While meeting participants are particularly encouraged to submit their work, the feature is open to all other researchers in the related area.

All activity in your brain – including those which mediates your perception of colour – is based on electrical messages between neurons. Vision scientists can measure these signals at the eye, and at the back of the brain.

How many colours we see is limited by our eye, which contains only three types of colour sensors. Using advanced techniques, vision scientists can take images of this “invisible” information and make it visible.

In early 2015, an image of a dress polarised the internet: Some people saw it as black-blue, and some as white-gold. Three years on, we revisit the dress and discuss how vision science can explain this phenomenon.

With Manuel Spitschan, Anya Hurlbert, Karl Gegenfurtner and David Brainard.